I. Field of the Invention
This invention relates generally to electrosurgical apparatus, and more particularly to an implement dimensioned so that it can be readily made to pass through the vascular system or an endoscope for facilitating the tunneling of the implement through a tissue body.
II. Discussion of the Prior Art
A variety of electrosurgical instruments are presently known and, for the most part, comprise a hand-held scalpel whose blade carries electrodes. The scalpel is adapted to be connected to a RF electrosurgical generator and when appropriately energized, the implement may be used for cutting tissue or coagulating blood. Typical of such a device is the apparatus shown in the Stasz U.S. Pat. No. 4,674,498 and Noerenberg et al U.S. Pat. No. 4,802,476.
Another electrosurgical implement has been designed to facilitate the removal of polyps from the inner wall of the intestine and it generally comprises a wire snare which is arranged to function as a first electrode, the wire also cooperating with an electrode mounted on the distal end of a flexible tubular member surrounding the wire. As the polyp is brought into contact with the both the snare and the conductive tip on the tube, an electric arc is created for severing the neck of the polyp while simultaneously cauterizing the site of the removal. An arrangement of this type is disclosed in the Rydell et al patent application Ser. No. 07/344,073, filed Apr. 17, 1988, now U.S. Pat. No. 4,905,691 and assigned to applicant's assignee.
Still various other electrosurgical implements have been devised for effecting single-purpose electrosurgical procedures. Until the present invention, a need has existed for an elongated, small diameter, flexible, atraumatic device which can be routed through a body channel to the site where cell tissue is to be pierced. For example, such a device may be used to drain a cyst or tumor located within the abdomen by routing the implement through an endoscope into the stomach or colon and from there, tunneling through the wall of the stomach or colon into the neighboring cyst whereby fluid can be readily drained from it.
In carrying out transluminal angioplasty, a need exists for a device which can be used to tunnel through atheromas to restore patency to more distal blood vessels.